package cn.yhp.chatgpt.infrastructure.util.sdk;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

/**
 * @author yhp
 * @description
 * @date 2024/1/8
 */
public class SignatureUtil {

    public static boolean check(String token,String signature,
                                String timestamp,String nonce) {
        String[] arr = {token, timestamp, nonce};
        // 将token timestamp nonce参数进行字典序排序
        Arrays.sort(arr);
        StringBuffer content = new StringBuffer();
        for (String s : arr) {
            content.append(s);
        }
        MessageDigest md;
        String tmpStr;
        try {
            md=MessageDigest.getInstance("SHA-1");
            // 将三个参数字符串拼接成一个字符串进行sha1加密
            byte[] digest = md.digest(content.toString().getBytes());
            tmpStr = byteToStr(digest);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
        // 将sha1加密后的字符串可与signature对比，标识该请求来源于微信
        return tmpStr.equals(signature.toUpperCase());
    }

    /**
     * 将字节数组转换为十六进制字符串
     */
    private static String byteToStr(byte[] byteArray) {
        StringBuilder strDigest = new StringBuilder();
        for (byte b : byteArray) {
            strDigest.append(byteToHexStr(b));
        }
        return strDigest.toString();
    }

    /**
     * 将字节转换为十六进制字符串
     */
    private static String byteToHexStr(byte mByte) {
        char[] Digit = {'0', '1', '2', '3', '4', '5', '6', '7', '8',
                '9', 'A', 'B', 'C', 'D', 'E', 'F'};
        char[] tempArr = new char[2];
        tempArr[0] = Digit[(mByte >>> 4) & 0X0F];
        tempArr[1] = Digit[mByte & 0X0F];
        return new String(tempArr);
    }
}
